He is known to be the outcast of the school and has little to no friends. During his time in South Park, he's been through a lot and while he may be an outcast, he is one of the most significant side characters of the show. He even had his own show where he found out his father was a homosexual (a returning joke in a few episodes) and his mother tried to kill him after finding out. He pretends to be an evil villain named Professor Chaos, and has tried (and failed) to end the world. He has been sent to a camp for homosexual boys where they tried to "pray the gay away". For one season, he ended up replacing Kenny in the main cast due to Kenny's death, where his friends constantly ridiculed him for not being as "cool" as Kenny. This was usually a (highly successful) tactic to get him to do what they wanted. Butters is extremely gullible and is often a guinea pig for the other boys' bad ideas, such as disguising himself as a girl named Marjorine.
Butters is also the evil villain Professor Chaos.